1. Field of the Invention
The invention relates to a position adjustment device for an integration rod used in an optical projection system.
2. Description of the Related Art
FIG. 1 shows a schematic diagram illustrating a conventional position adjustment device for an integration rod. Referring to FIG. 1, the position adjustment device is provided in a housing 102 of an optical engine to adjust the position of an integration rod 104 in the shape of a rectangular parallelepiped in the housing 102. The position adjustment device includes a fixed plate 106. The fixed plate 106 cooperates with the housing 102 to accommodate the integration rod 104, two resilient sheets 108 and 110, and adjusting screws 112 and 114 inserted through the housing 102 in an X-axis direction and a Y-axis direction, respectively. Further, the adjusting screws 112 and 114 press against the integration rod 104. When fastened, the adjusting screws 112 and 114 are fed in the X-axis direction and Y-axis direction, respectively, and, meanwhile, the elastic force of the resilient sheets 108 and 110 enables the integration rod 104 to continually keep in contact with the adjusting screws 112 and 114 so as to achieve a two-dimensional position adjustment for the integration rod 104.
However, in the conventional design shown in FIG. 1, the two adjusting screws 112 and 114 make an angle of 90 degrees with each other and their respective insertion directions are not a vertical or a horizontal direction. Hence, the use of adjusting screws 112 and 114 making the two-dimensional position adjustment is liable to interfere with other components in the housing 102. In that case, the entire optical engine is disassembled and fixed by a jig during the process of position adjustment. This is very inconvenient for the operation on position adjustment or damage repair.
FIG. 2 shows a schematic diagram illustrating another conventional position adjustment device for an integration rod. Referring to FIG. 2, the position adjustment device and the integration rod 200 are both provided in a housing 202. The position adjustment device, which permits position adjustments in X-axis direction and Y-axis direction to the integration rod 200, includes a fixed plate 204, two resilient sheets 206 and 208, two adjusting screws 210 and 212, and two push members 214 and 216. The push member 214 is provided between the adjusting screw 210 and the integration rod 200, and the push member 216 is provided between the adjusting screw 212 and the integration rod 200. The resilient sheets 206 and 208 are positioned opposite the push members 214 and 216, respectively. Besides, the resilient sheets 206 and 208 press against the integration rod 200. When the adjusting screws 210 and 212 are inserted through the housing 202 and push the push members 214 and 216, respectively, the components of force from push members 214 and 216 force the integration rod 200 to move in the X-axis direction and Y-axis direction, and, meanwhile, the elastic force of the resilient sheets 206 and 208 enables the integration rod 200 to continually keep in contact with the push members 214 and 216 so as to achieve a two-dimensional position adjustment for the integration rod 200.
In the conventional design shown in FIG. 2, though the effect that the two adjusting screws 210 and 212 are inserted through the housing 202 in a same direction is obtained, the additionally provided push members 214 and 216 increase the number of constituting members and fabrication costs.